Question

If in the circuit shown in Fig. power dissipation is 150 W, then find the value of R (in $\Omega$).

Answer 1

Given:

$R,=2\Omega V=15V$

The equivalent resistance of the circuit is $R_{eq}=\frac{2R}{2+R}$
Power dissipation , $P=\frac{V^2}{R_{eq}}$
$R_{eq}=\frac{V^2}{P}$

$\Rightarrow \frac{2R}{2+R}=\frac{{15}^2}{150}=\frac{15\times 15}{150}=3/2$

$4R=6+3R\Rightarrow R=6\Omega$